KR101620117B1 - Improved extractive distillation processes using water-soluble extractive solvents - Google Patents
Improved extractive distillation processes using water-soluble extractive solvents Download PDFInfo
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Abstract
Soluble Extractive Distillation (ED) The extractive distillation process, in which the solvent is regenerated and recovered, introduces improved operation of the EDC (extractive distillation column) to produce polar and low polar hydrocarbons and the intended feedstock produced in the ED process The polar hydrocarbons are recovered and purified from a mixture containing a measurable amount of hydrocarbons heavier than the polymer. The improved process can remove and recover heavy hydrocarbons from the solvent and / or effectively remove polymer contaminants in the waste solvent circulation loop through mild operating conditions, without consuming additional process energy. With the improved process, the upper reflux of the EDC is eliminated, further reducing the energy consumption and improving the mounting and performance within the top of the EDC, especially if the two liquid phases are on top of the EDC.
Description
The present invention relates generally to an extractive distillation process in which an aqueous extractive distillation (ED) solvent is efficiently regenerated and recovered, more specifically, polar hydrocarbons have polar and low polarity hydrocarbons, To an improved operation of an extractive distillation column (EDC) that is efficiently recovered and purified from a mixture containing a heavier, measurable amount of hydrocarbons, and / or polymers produced in the ED process. The improved process removes heavy hydrocarbons and polymers from solvents in the waste solvent circulation loop under mild operating conditions.
In extractive distillation, a non-volatile polar solvent is added to the EDC to increase the relative volatility between polar and low polarity components having near boiling points. Generally, the solvent is added to the top of the EDC and the hydrocarbon feed is introduced to the middle of the EDC. As the non-volatile solvent descends through the column, the polar component is preferentially extracted to form a rich solvent moving toward the bottom of the EDC, causing the vapor of the low polarity component to rise to the top of the column. The vapor at the top is condensed and a portion of the condensate is recirculated to the top of the EDC as reflux while the remainder is discharged to the raffinate product. The rich solvent stream containing the solvent and the polar components is fed to a solvent recovery column (SRC) to recover the polar component as an overhead product and recover the lean solvent as a bottom product , Which is recycled to the top of the EDC and re-used as the extraction solvent. A portion of the overhead product is recirculated as reflux to the top of the SRC to drop any entrained solvent of the top steam down. The SRC is optionally operated under reduced pressure (vacuum) and / or with a stripping medium to lower the temperature of the bottom of the tower.
The ED process for separating aromatic and non-aromatic components is described in US Patent No. 7,078,580 to Tian et al., U.S. Patent No. 4,053,369 to Cines and F. Lee, "Two Liquid-Phase Extractive Distillation for aromatics Recovery", Ind. Eng. Chem. Res. (26) No. 3, 564-573, 1987. The ED technique for separating the diolefin and olefin components is described in Patel U.S. Pat. No. 4,269,668, and is described in ED Technology for separating cycloparaffins and paraffins Quot; Way To Purify Cyclohexane ", R. Brown et al., Hydrocarbon Processing, 83-36, May 1991. Finally, the ED process for separating styrene and C 8 aromatics is described in U.S. Patent No. 5,849,982 to Lee et al.
The recovery of aromatic hydrocarbons from a mixture containing aromatic and non-aromatic hydrocarbons can be achieved through liquid-liquid extraction (LLE) or ED. The ED process requires fewer equipment than the LLE process, for example ED requires two separate columns compared to a LLE that generally requires four separate columns. In addition, ED generally requires less energy and faces less operational problems; However, the application of the ED process is limited by the boiling point range of the feedstock. Thus, in order for the ED process to achieve an acceptable level of purification and recovery of the aromatics, the solvent should basically contain all benzene, which is the lightest with a boiling point (BP) of 80.1 DEG C below the EDC An aromatic compound; Additionally, the process should virtually move all the highest quality non-aromatics to the top of the EDC. In the case of a narrow boiling point-ranging (C 6 -C 7 ) aromatic feedstock, the heaviest non-aromatic compound may be ethylcyclopentane (BP: 103.5 ° C) while a complete boiling point-range of C 6 For the C 8 ) aromatic feedstock, the highest quality non-aromatics may be ethyl cyclohexane (BP: 131.8 ° C). Obviously, complete Boiling-range feed of the raw material, for example, is the recovery of benzene, toluene and xylene (BTX) aromatics from a full range pyrolysis gasoline, narrow boiling point-range feedstock, such as benzene, C 6 -C 7 from the oil production And recovery of toluene is much more difficult. An ED process suitable for narrow boiling point-range aromatic feedstocks may not be able to satisfactorily process a complete boiling-point aromatic feedstock.
Another major problem associated with the ED process for aromatics hoesueul is to measure the amount of heavy (C 9 -C 12) hydrocarbon feedstocks available in the ED is present, which can lead to failure of the process in serious conditions. This problem requires special attention to the recovery of the BTX aromatics from the complete boiling-point (C 6 -C 8 ) feedstock. For recovery of the aromatics in the ED and LLE processes, the solvent is cycled indefinitely in the closed loop structure. In order to remove the heavy hydrocarbons and the macromolecular heavy material from the oxidized solvent, a commercial LLE process requires that a small slipstream of the lean solvent (about 1% lean solvent stream) is heated without or with the use of stripping vapors A regenerated solvent having a boiling point lower than the boiling point of the solvent and / or a solvent regenerator for recovering any heavy components. The heavy polymer material having a boiling point higher than the boiling point of the solvent is removed from the bottom of the solvent regeneration zone with sludge.
The solvent regeneration structure disclosed in Asselin U.S. Patent No. 4,048,062 has been successfully implemented in the UOP and IFP LLE aromatics recovery process using sulfolane and an extraction solvent. The reason for such success is that most of the heavy (C 9 -C 12 ) hydrocarbons in the feedstock are removed by the solvent phase in the LLE column and removed along the raffinate phase as part of the non-aromatic product. Only a portion of the C 9 aromatics is extracted by the solvent and they can be effectively stripped from the solvent under normal operating conditions in SRC.
However, in a typical EDC operation for the recovery of aromatics, such heavy hydrocarbons tend to leave a rich solvent in the bottom of the EDC due to its high boiling point. In the case of complete boiling-point (C 6 -C 8 ) feedstocks, the high boiling point of the heavier hydrocarbons prevents them from being stripped from the solvent in the SRC such that the heavy hydrocarbons are in the closed loop between the EDC and the SRC, As shown in FIG. The solvent regeneration structure described in U.S. Patent No. 4,048,062 can not be applied to the ED process because it can not be used for the LLE to remove a small amount of polymeric material that can form from the reaction between the oxidized or degraded solvent component and the traces of heavy hydrocarbons in the solvent It is designed for process. The industry needs a way to properly remove heavy hydrocarbons and / or polymers from the lean solvent of the ED process to recover the aromatics.
Mixtures of C 4 hydrocarbons containing different degrees of saturation of C 4 , such as mixtures of butane and butene, and mixtures of 1,3 butadiene with butane and butene, are generally fractionated due to the similar boiling points of the components and the formation of azeotropes It is not easily separated by distillation. However, such a mixture selectively separates one or more of the more unsaturated components and is more efficiently separated into the respective components by an ED process using a water-soluble solvent having a relatively higher boiling point. Commercially available solvents include furfural, acetonitrile, dimethyl formamide, dimethyl acetamide and N-methyl pyrrolidone, 3-methoxy Propionitrile (3-methoxy propionitrile) and mixtures thereof with water. U.S. Patent Nos. 3,309,412 and 3,551,507, Sakuragi et al., Recognized the macromolecularization of butadiene in the ED process and found that the addition of small amounts of inhibitors such as furfural, benzaldehyde, nitrophenol or dinitrophenol in solvents To minimize this problem. Inhibitors inhibit polymerisation, but the accumulated polymer should still be removed from the lean solvent.
U.S. Patent No. 5,849,982 to Lee et al. Discloses an ED process for recovering styrene from the C 8 portion of pyrolysis gasoline, which includes propylene carbonate, sulfolane, methyl carbitol, A water-soluble solvent containing a mixture of 1-methyl-2-pyrrolidone, 2-pyrrolidone and water is used. Although styrene tends to form polymers under thermal conditions, no polymer inhibitors are added to this process. The lean solvent was regenerated with a conventional solvent regenerator using energy from heat of steam stripping and reheating. The ED process may not remove all the generated polymers.
Current extraction solvents for liquid-liquid extraction or extractive distillation are water-soluble and are especially water-soluble, especially sulfolane, polyalkylene glycols, N-substituted morpholine, furfural, acetonitrile, dimethyl Formamide, dimethylacetamide, N-methylpyrrolidone and 3-methylpropionitrile. Indeed, since they are water-soluble, the extraction solvent is removed from the raffinate vapors produced in the extraction zone of the LLE process by counter-current or water-current extraction using water, Raffinate product vapor can be produced. The solvent is partially present in the raffinate vapor at low concentrations as an equilibrium constituent and may be partially present in the entrained dispersion of the solvent-free phase due to turbulence in the extraction zone. Purification of the aromatics through the LLE process is further described in Asselin, U.S. Patent No. 4,419,226, wherein the solvent component comprises sulfolane and water and is further described in Stephens US Patent No. 2,773,918 wherein the solvent is poly Alkylene glycol and water. Both techniques involve the extraction of a water soluble solvent with water from non-aromatic raffinate vapors present in the extraction zone of the LLE process. The water-soluble nature of the solvent may be used to maintain the concentration of the co-solvent in the solvent mixture as disclosed in U. S. Patent No. 6,551,502 to Lee et al.
In a typical distillation column, the liquid reflux at the top is necessary to produce a liquid phase in the rectification zone of the column, which is a tray-to-tray for separating the main constituents in the feed mixture. Lt; / RTI > Depending on the application, the typical reflux-to-distillate ratio in the distillation column is about 1 to 20. However, in EDC, the liquid phase in the rectification zone is non-volatile and polar solvent, which absorbs more polar components from the preferentially rising vapor phase and causes the low polarity component vapor to rise to the top of the EDC. The present inventors have found that adding reflux to EDC may not significantly improve the purity and recovery of the EDC top product (raffinate). Its sole purpose is to drop the entrained solvent in the raffinate product. In fact, the elimination of the EDC reflux can significantly reduce the vaporization of the bottom reheater and reduce the vapor loading at the top of the column, thereby increasing the throughput of the clam.
Finally, if the extraction solvent has a very limited solubility of the low polarity component in the raw material mixture, two liquid phases can be generated in the EDC. For example, an ED process for the purification of aromatics using sulfolane containing water as a solvent is disclosed in Cines, U. S. Patent No. 4,053, 369, wherein the two liquid phases are on top of the EDC. This is because sulfolane has a very limited solubility for the low polarity non-aromatics, which is concentrated on top of the EDC. However, unlike Cines' disclosure, the present invention recognizes that the presence of two liquid phases within the EDC is undesirable and can cause many potential operational problems with the EDC. Limited experimental data available in the literature suggest that the tower (or tray) efficiency is very low and highly variable in the range of 25-50% in the two liquid phase regions. Adding the reflux to the EDC causes the expansion of the two liquid phase regions at the top of the EDC because the reflux is essentially 100% raffinate, which is less soluble in the solvent. Without EDC reflux, different methods must be developed to remove entrained solvents in the raffinate product from the EDC overhead stream.
It is an object of the present invention to provide an improved extractive distillation process using a water-soluble extraction solvent.
The present invention relates to an extractive distillation process that introduces an improved lean solvent regeneration system that significantly reduces the amount of heavy hydrocarbons and / or polymers that are fixed in the waste solvent loop. According to the present invention, excellent solvent performance can be obtained, the amount of solvent regenerated per cycle is reduced, and, if necessary, the values of heavy hydrocarbons can be recovered. The present invention can be achieved by replacing the lean solvent regenerator of a conventional high temperature, energy intensive and difficult to operate conventional extractive distillation system with a low temperature, energy saving and easy to operate flush system. The original lean solvent regenerator can be optionally maintained, but operates with a significantly reduced capacity as an auxiliary unit for the new flush system.
In one aspect, the present invention relates to an extractive distillation process in which a polar hydrocarbon-selective water-soluble solvent is recovered from a stream containing a polar hydrocarbon-selective water-soluble solvent and a measurable amount of heavy hydrocarbons and sludge,
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low-polarity hydrocarbon stream containing water from the top of the EDC and discharging a first solvent stream containing a polar hydrocarbon-selective water-soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering a polar hydrocarbon stream from the top of the SRC that is substantially free of a polar hydrocarbon-selective water soluble solvent and a low polar hydrocarbon, and Removing a second solvent stream containing a lean solvent from the bottom of the SRC;
(d) introducing a large portion of the second solvent stream into the top of the EDC in step (a) as a polar hydrocarbon-selective aqueous solvent stream, and introducing a small portion of the second solvent stream into the heavy hydrocarbon removal zone step;
(e) separating the first water stream from the lower polarity hydrocarbon stream containing water recovered from the top of the EDC in step (b) and separating the second water stream from the polar hydrocarbon stream recovered from the top of the SRC in step (c) Separating the stream;
(f) introducing at least a portion of the first water stream and at least a portion of the second water stream into a heavy hydrocarbon removal zone, recovering the polar hydrocarbon-selective water-soluble solvent in an aqueous phase, In an oil phase;
(g) withdrawing the accumulated oil phase containing heavy hydrocarbons from the heavy hydrocarbon removal zone and recovering the aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the heavy hydrocarbon removal zone;
(h) separating water from the low polarity hydrocarbon stream containing water of step (b) to produce a low polarity hydrocarbon stream introduced into the solvent removal zone and a portion of the first water stream from step (e) 2 water stream or a portion of both the first and second water streams to the solvent removal zone thereby extracting the entrained polar hydrocarbon-selective water-soluble solvent and removing the low polarity hydrocarbon;
(i) withdrawing the accumulated oil phase containing low-polarity hydrocarbons from the solvent removal zone and recovering the aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the solvent removal zone;
(j) removing the tramp iron and polymer sludge from the aqueous phase from step (g) to obtain an aqueous phase free of solid matter; And
(k) introducing a solid phase free aqueous phase from step (h) and step (j) into the vapor generator and evaporating the water to produce a stripping vapor introduced into the lower portion of the SRC in step (c) .
In another aspect, the present invention relates to an extractive distillation process in which a polar hydrocarbon-selective water-soluble solvent is recovered from a stream containing a polar hydrocarbon-selective water-soluble solvent and a measurable amount of heavy hydrocarbons and sludge,
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low-polarity hydrocarbon stream containing water from the top of the EDC and discharging a first solvent stream containing a polar hydrocarbon-selective water-soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering a polar hydrocarbon stream from the top of the SRC that is substantially free of a polar hydrocarbon-selective water soluble solvent and a low polar hydrocarbon, and Removing a second solvent stream containing a lean solvent from the bottom of the SRC;
(d) introducing a large portion of the second solvent stream into the top of the EDC in step (a) as a polar hydrocarbon-selective aqueous solvent stream, and introducing a small portion of the second solvent stream into the heavy hydrocarbon removal zone step;
(e) separating the first water stream from the lower polarity hydrocarbon stream containing water recovered from the top of the EDC in step (b) and separating the second water stream from the polar hydrocarbon stream recovered from the top of the SRC in step (c) Separating the stream;
(f) introducing at least a portion of the first water stream and at least a portion of the second water stream into a heavy hydrocarbon removal zone, recovering the polar hydrocarbon-selective water-soluble solvent which is an aqueous phase, and removing the heavy hydrocarbon in the oil phase ;
(g) withdrawing the accumulated oil phase containing heavy hydrocarbons from the heavy hydrocarbon removal zone and recovering the aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the heavy hydrocarbon removal zone;
(h) recycling at least a portion of the low polarity hydrocarbon stream separated from the first water stream in step (e) to the top of the EDC to drop the entrained polar hydrocarbon-selective water-soluble solvent in the EDC top vapor to substantially remove the polar hydrocarbon - producing a low polarity hydrocarbon stream that does not contain a selective water soluble solvent;
(j) removing foreign matter and polymer sludge from the aqueous phase from step (g) to obtain an aqueous phase free of solid matter; And
(k) introducing the solid phase free aqueous phase from step (j) into the vapor generator and evaporating the water to form stripping vapor entering the bottom of the SRC in step (c).
In another aspect, the present invention relates to an extractive distillation process in which a polar hydrocarbon-selective water-soluble solvent is recovered from a stream containing a polar hydrocarbon-selective water-soluble solvent and a measurable amount of heavy hydrocarbons and sludge, :
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low-polarity hydrocarbon stream containing water from the top of the EDC and discharging a first solvent stream containing a polar hydrocarbon-selective water-soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering from the top of the SRC a substantially polar hydrocarbon-selective aqueous solvent and a polar hydrocarbon stream free of low polarity hydrocarbons, Removing a second solvent stream containing a lean solvent from the bottom of the first solvent stream;
(d) introducing a large portion of the second solvent stream to the top of the EDC in step (a) as a polar hydrocarbon-selective aqueous solvent stream, and introducing a small portion of the second solvent stream to the bottom of the flushing zone step;
(e) separating water from the low-polarity hydrocarbon stream containing water recovered from the top of the EDC in step (d) and separating the low-polarity hydrocarbon stream introduced into the flushing zone from the inflow point located below the inflow point of the second solvent stream And a first water stream;
(f) separating the first water stream from the lower polar hydrocarbon stream containing water to be removed in step (b) and separating the second water stream from the polar hydrocarbon stream recovered from the upper portion of the SRC in step (c) step;
(g) introducing at least a portion of the first water stream and the second water stream to the top of the flush zone, recovering the polar hydrocarbon-selective water-soluble solvent which is an aqueous phase, and removing the polar hydrocarbon and heavy hydrocarbons in the oil phase step;
(h) discharging an accumulated oil phase containing low-polarity hydrocarbons and heavy hydrocarbons from the top of the flush zone and discharging an aqueous phase containing a polar hydrocarbon-selective water-soluble solvent and any sludge from the bottom of the flush zone ;
(i) removing foreign matter and polymer sludge from the aqueous phase of step (h) to obtain an aqueous phase free of solid matter; And
(j) introducing the solid phase free aqueous phase from step (i) into the vapor generator and evaporating the water to form a stripping vapor entering the bottom of the SRC in step (c).
The novel process features of the present invention will greatly improve the extractive distillation process with the following unexpected effects by eliminating the upper liquid reflux of the EDC: (1) steam consumption is reduced, (2) more (3) minimizing the two liquid phase regions, if present, to improve solvent performance at the top of the EDC, and (4) if present, Minimizing the two liquid phase regions improves the tray efficiency at the top of the EDC.
1 is a schematic flow chart of an extractive distillation process using a conventional thermal solvent regenerator (base example).
Figure 2 is a schematic flow diagram of an extractive distillation process using two flushing systems to separately clean the raffinate stream and regenerate the lean solvent.
Figure 3 is a schematic flow diagram of an extractive distillation process using a single flush system to wash the raffinate stream and regenerate the lean solvent.
Figure 4 is a schematic flow diagram of an extractive distillation process using a single flush system with an auxiliary thermal solvent regenerator to wash the raffinate stream and regenerate the lean solvent.
5 is a schematic flow diagram of a single flush system for washing a raffinate stream and an extractive distillation process using a thermal regenerator to regenerate lean solvent.
Figure 6 is a schematic flow diagram of an extractive distillation process using a single flush system to regenerate the lean solvent.
The present invention relates to an extractive distillation process for removing heavy hydrocarbon and / or polymer contaminants as well as for separating and recovering polar hydrocarbons from low polarity hydrocarbons. The separation is carried out through the use of a water-soluble extractive distillation solvent which is characteristically selective to absorb polar hydrocarbons. The terms "polar" and "less polar" are used to distinguish between classes of hydrocarbons, and one particular type has a greater polarity than the other. The present invention is particularly suitable for applications in which the feedstock component contains a mixture of polar and low polarity hydrocarbons. Such mixtures include: (1) aromatic and non-aromatic materials, (2) diolefins and olefins, (3) naphthens and paraffins, or (4) styrene and C 8 aromatics. Exemplary water soluble solvents include sulfolane, polyalkylene glycol, N-substituted morpholine, furfural, acetonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 3-methoxypropionitrile and ≪ / RTI > Preferably water is added as a cosolvent.
The choice of a water-soluble solvent to be used depends, inter alia, on the feedstock component and the required byproduct. Aqueous sulfolanes or aqueous N-formylmorpholines are particularly suitable solvents when the feedstock comprises aromatic and non-aromatic materials. Aqueous dimethylformamide is particularly suitable when the feedstock comprises butadiene and C 4 olefins, and aqueous sulfolanes are particularly suitable when the feedstock comprises styrene and C 8 aromatics.
During operation of the EDC (extractive distillation column), the liquid phase in the rectification zone is comprised of a non-volatile solvent, which primarily absorbs the polar component from the ascending vapor phase and causes the vapor of the low polar component to rise to the top of the EDC. Using a 3 meter diameter EDC that was used for BTX aroma recovery, it has been demonstrated that adding reflux to the EDC does not improve the purity or recovery of the EDC top product, i.e., non-aromatic raffinate. This feature was confirmed by the operation of a one-meter diameter EDC to recover the anhydrous ethanol from the fermented dead, where the purity and recovery of anhydrous ethanol were observed to be the same regardless of whether EDC reflux was introduced or not. In other cases, the unique purpose of reflux was to drop the entrained solvent from the EDC top product. Thus, the elimination of the EDC reflux was expected to significantly reduce steam consumption at the bottom reheater and reduce the steam entering the top of the column, thereby increasing the throughput of the tower.
If the extraction solvent has a very limited solubility for the low polarity components in the raw material mixture, two liquid phases can be generated in the EDC, especially at the top of the column. In this case, introducing the reflux into the EDC will cause the two upper liquid phase regions to swell because the reflux consists essentially of raffinate of low solubility. The presence of the second liquid phase not only affects solvent performance, which affects the separation factor between the polar component and the less polar component, but may also change the mass transfer efficiency in the EDC. For example, sulfoline solvents use water as co-solvent to improve their selectivity in the separation of aromatic and non-aromatics. Since water has a relatively low boiling point (high volatility), the sulfolane solvent in the top of the EDC has the highest water content. However, the literature data show that, in the two liquid phase regions, the presence of water in sulfolane is actually adversely affecting the separation. To illustrate the adverse effects of water on the sulfolane solvent in the two liquid phase regions, the following equilibrium constants are obtained for the following (see, for example, Lee et al., "Extractive Distillation Under Two Liquid Phase ", 1987 AIChE Summer National Meeting, Minneapolis, Minn. Data are cited from this document: < RTI ID = 0.0 >
Effect of water (co-solvent) on selectivity of sulfolane under two liquid phases
Pressure: 75.0 cm Hg (absolute pressure)
Total liquid component: 50% by weight of n-heptane and 50% by weight of toluene
Data from one stage balance cell
Water included Vapor composition (% by weight) Liquid number
S / F: weight ratio of solvent to hydrocarbon
R: Solvent selectivity = (heptane in the vapor / heptane in the liquid) / (toluene in the vapor / toluene in the liquid)
Table 1 shows that, in the two liquid phase regions, the presence of water significantly reduces the sulforene selectivity at all solvent to hydrocarbon ratios (S / F). Further, if the two liquid phases are not completely mixed, the above-mentioned commercial operation of a 3 meter diameter EDC, which exhibits irregular behavior causing the tower to fail when operating variably, is changed. Therefore, it is not desirable to add reflux (insoluble raffinate) to the EDC, since sulfolane will cause expansion of the two liquid phase regions at the top of the column when sulfolane is used as the solvent for the recovery of the aromatics. If there is no liquid reflux in the EDC to drop the entrained solvent, the EDC top product (raffinate) may contain undesirable levels of solvent depending on the EDC top configuration.
Upon introducing the novel extractive distillation process of the present invention, the solvent containing raffinate is fed into the flush system to reduce the solvent components in the raffinate to the desired level as long as the solvent can be dissolved in water. In a preferred process configuration, the raffinate is fed to the bottom of the backwash extraction tower, which includes multi-stage contact trays or packings, while at the same time the wash water is introduced into the top of the tower. In the application of the ED process for the recovery of aromatics, the wash water is discharged from the water legs of the upper receptacle from both EDC and SRC. The water containing solvent removed from the bottom of the flush tower can be fed to the bottom of the SRC to recover the solvent as well as produce stripping vapors. Since water is already required to produce stripping vapors for SRC, raffinate water washing does not require additional energy. The raffinate washed with water accumulates on the hydrocarbon near the top of the wash tower and is recovered as a solvent free raffinate product.
In another preferred embodiment of the present invention, the slip stream of the lean solvent is fed to the bottom of the same flush system for the washing of the EDC raffinate stream, instead of being fed to a separate flush system, to remove and recover heavy hydrocarbons, The polymer is removed from the solvent. Characteristics of the Invention for Recovery of Aromatic Materials In an embodiment, the slip stream of lean solvent is fed to the bottom of the multi-stage backwash flush tower at a point just above the inflow point of the raffinate feed from the top of the EDC. The amount of wash water fed to the top of the wash tower is adjusted so that essentially all of the EDC raffinate and heavy hydrocarbons from the lean solvent, if present, are recovered from the top of the wash tower. Although both the EDC upper raffinate stream and the slipstream of the lean solvent are both fed into the same flush top, even though the wash water full of solvent from the bottom of the flushing tower contains more solvent as it is recycled to the SRC for the production of stripping vapors, Does not generally require additional washing water. Therefore, no additional energy is required. The magnetic filter is installed at the bottom outlet of the flush tower to continuously remove trace amounts of foreign matter, polymer sludge and other polar impurities.
A. Extractive distillation using conventional solvent regeneration (basic example)
The extractive distillation process shown in FIG. 1 introduces a thermal SRG1 (solvent regenerator) having an extractive distillation column (EDC1), a solvent recovery column (SRC1) and a vapor stripping. A hydrocarbon feed containing a mixture of polar and low polarity components is fed via
The solvent-to-hydrocarbon feed ratio (S / F), the lower temperature of the EDC1, the pressure of the EDC1, and the hydrocarbon feedstock location allow the desired separation between the upper raffinate and the lower rich solvent to be achieved Are parameters that are adjusted to provide the necessary conditions.
The upper raffinate is discharged from the top of the
A rich solvent stream containing solvent, polar hydrocarbons and a measurable amount of heavy hydrocarbons and / or polymers is discharged from the bottom of
The water phases accumulated in the water legs of the upper accumulators of D1 and D2 are optionally transferred to the water drum WD via
The slip stream is withdrawn from the lean solvent recycle loop and fed via
Thermal stripping to regenerate the lean solvent has been developed for liquid-liquid extraction for the recovery of aromatics. In this process, a measurable amount of heavy (C 9 to C 12 ) hydrocarbons in the feedstock is removed by the solvent phase in the LLE tower and removed using the raffinate phase as part of the product of the non-aromatic material. Only C 9 aromatics tend to be extracted by the solvent, and they are mainly stripped from the solvent in a solvent recovery column (SRC) under normal operating conditions. Thus, if the ED feedstock contains a noticeable amount of heavy (C 9 -C 12 ) hydrocarbons, or if the components in the feedstock tend to polymerize under thermal conditions, the thermal solvent regenerator (SRG1) will be extremely unsuitable . If any of these situations occurs, the process becomes impossible.
B. Extraction distillation with two flushing systems to wash the raffinate stream and separately regenerate the lean solvent
The extractive distillation process shown in FIG. 2 includes an extractive distillation column (EDC2), a solvent recovery column (SRC2), a solvent removal zone, a WWC2 (water-wash column) for removing entrained solvent from a raffinate stream of EDC2, And a heavy hydrocarbon stripping zone in the form of a WWC3 (water-wash column) for regenerating the lean solvent, for example. The main differences between the basic process of FIG. 1 and the novel process are: (1) the elimination of EDC reflux which saves energy in reheating (R3) and potentially increases the throughput of EDC2, (2) Use of a low cost WWC2 (water-waas system) that removes entrained solvent and is preferably a countercurrent extraction tower and consumes minimal energy or does not consume energy in essence, and (3) improper, High-cost, low-temperature, low-cost WWC3 (water-wash) for regenerating high-cost thermal solvent regenerators, which can contain excessive amounts of heavy hydrocarbons and / or polymers that can render the thermal solvent regenerator non- system.
The hydrocarbon feed is fed via
The upper raffinate is condensed in the cooler C3 before being discharged from the top of the
A rich solvent stream containing solvent, polar (extraction) hydrocarbons and detectable heavy hydrocarbons and / or polymers is discharged from the bottom of
The stripping vapor produced from the steam generator SR2 is injected into the bottom of the SRC2 via
In order to remove heavy materials, including any foreign matter, heavy hydrocarbons, polymer sludge and any other polar material, from the lean solvent, the slip stream is discharged from the lean solvent recycle loop and is preferably withdrawn as a separate flushing system (WWC3) . The slipstream represents only a small fraction (typically 1 to 2%) of the lean solvent stream. If the density of the solvent is higher than the density of water, the lean solvent is preferably fed to the top of
The heavy hydrocarbon removal zone may include various devices including, for example, a continuous multi-stage countercurrent contact device, a multi-stage mixer / precipitator or a rotary contactor. The heavy hydrocarbon removal zone may be a water tank that functions as a decanter for separating heavy hydrocarbons and any sludge from the aqueous phase containing water soluble solvent and water. Similarly, the solvent removal zone may include a variety of devices including, for example, a continuous multi-stage countercurrent contact device, a multi-stage mixer / precipitator or a rotary contactor. The solvent removal zone may be a tank in which low polarity hydrocarbons are separated from an aqueous phase containing water with a trace amount of a water soluble solvent. Both the heavy hydrocarbon removal zone and the solvent removal zone are preferably maintained under mild conditions at a temperature of 25 to 80 DEG C and a pressure of 1 to 10 atmospheres and at a wash-to-solvent feed weight ratio of 0.5 to 10, Lt; / RTI >
In one embodiment, the feedstock comprises aromatic and non-aromatic materials and the EDC operates under conditions that maximize benzene recovery in the first solvent-enriched stream by retaining substantially all of the C < 9 > + hydrocarbons in the first solvent- do. In another embodiment, the feedstock comprises aromatic and non-aromatic materials, wherein the SRC strips only C 8 and light hydrocarbons from the first solvent-rich stream and feeds substantially all of the C 9 and heavy hydrocarbons to the second solvent- As shown in Fig.
As further described herein, the novel process of the present invention can be modified to include the following: (1) a single flush system for lean solvent regeneration, and removal of the entrained solvent (2) one flush to remove trace amounts of solvent in the raffinate produced from the novel EDC without reflux, and (2) to remove the trace amount of solvent in the raffinate from the fresh EDC without reflux, System, and the lean solvent can be regenerated from a conventional thermal solvent regenerator.
C. Extraction distillation with a single flush system to wash the raffinate stream and regenerate the lean solvent
The extractive distillation process shown in Figure 3 includes a single WWC4 (water-wash column) introduced to remove solvents from the extractive distillation column (EDC3), the solvent recovery column (SRC3) and the EDC raffinate stream and to regenerate the lean solvent do. The main differences between the basic process and this novel process are: (1) eliminating the EDC reflux to reduce the energy required for reheating (R5) and potentially increasing EDC throughput; and (2) Removal of entrained solvent from raffinate in a low-cost WWC4 (water-wash system) without essentially requiring energy, and (3) removal of the conventional thermal solvent regenerator with a dual-function water-wash system ) To regenerate a lean solvent which may contain an excessive amount of heavy hydrocarbons or polymers.
The hydrocarbon feed is fed via
A rich solvent stream containing solvent, polar hydrocarbons and detectable heavy hydrocarbons or polymer is discharged from the bottom of
The stripping vapor generated from the steam generator SR3 is injected into the lower portion of SRC3 via
To remove heavy materials, including any foreign matter, heavy hydrocarbons, polymer sludge, and other polar materials, from the lean solvent, the slipstream is discharged from the lean solvent recycle loop and after cooling through the cooler (C8), the EDC raffinate stream From the entry point above the entry point to the bottom of
D. Extractive distillation with a single flush system to wash the raffinate stream and regenerate the lean solvent using an auxiliary thermal solvent regenerator
Referring to FIG. 4, the process includes a WWC 5 (water-wash column) functioning to regenerate extractive distillation column (EDC 4), solvent recovery column (SRC 4) and lean solvent as well as to remove the solvent from the EDC raffinate stream do. The main difference between the process structure shown in FIG. 3 and the process structure in FIG. 4 is that the conventional thermal solvent regenerator (SRG2), which serves as an auxiliary unit for reducing the load of the dual function water-wash system (WWC5) ). The operation and conditions of the extractive distillation column (EDC4), the solvent regeneration column (SRC4) and the water-wash column (WWC5), although some minor adjustments may be required to accommodate the addition of the thermal solvent regenerator (SRG2) Is similar to the corresponding unit shown in Fig. This extractive distillation process using a single flush system is advantageous in that an excess amount of (i) foreign matter, (ii) sludge produced by the polymerisation of active components in the hydrocarbon feedstock, and / or (iii) Lt; RTI ID = 0.0 > ED < / RTI > process applications.
The hydrocarbon feed is fed via
The upper raffinate is condensed in the cooler C9 before being discharged from the top of the
A rich solvent stream containing solvents, polar hydrocarbons and detectable heavy hydrocarbons and / or polymers is discharged from the bottom of
The slip stream from the lean solvent recycle loop is removed by (1) cooling through cooler (C11), followed by removal of the EDC4 raffinate stream < RTI ID = 0.0 > (Water-wash column) via
WWC5 is efficient in removing excess heavy hydrocarbons as a valuable by-product from lean solvents, while SRG2 better removes foreign matter and polymer sludge, despite higher energy costs and limited capacity. Thus, the portion of the slip stream converted to WWC5 and SGR2 can be adjusted to accommodate the composition of the lean solvent. SRG2 may be considered to be an auxiliary unit for WWC5.
A single flush system for washing the E. raffinate stream and an extractive distillation process with a thermal regenerator to regenerate the lean solvent
The extractive distillation process shown in FIG. 5 includes an extractive distillation column (EDC 5), a solvent recovery column (SRC 5), a water-wash column (WWC 6) to remove entrained solvent from the EDC raffinate stream, And a conventional thermal SRG3 (stripping regenerator). This process eliminates the use of liquid reflux at the top of the
The hydrocarbon feed is fed via
A rich solvent stream containing solvent, polar hydrocarbons and detectable heavy hydrocarbons and / or polymers is discharged from the bottom of
Water filled with a solvent containing any foreign matter, polymer sludge or any other polar material is discharged from the bottom of the
F. Extractive distillation process with a single flush system to regenerate the solvent
The extractive distillation process shown in FIG. 6 is an energy-saving and easy-to-operate low-temperature alternative to an extractive distillation column (EDC6), a solvent recovery column (SRC6) and a generally high temperature, energy- And a WWC7 (water-wash system). This process is particularly effective when the lean solvent contains an excessive amount of heavy hydrocarbon and / or polymer sludge that can not be effectively removed from the lean solvent by conventional thermal stripping regenerable groups.
The hydrocarbon feed is fed via
The
A rich solvent stream containing solvents, polar hydrocarbons and detectable heavy hydrocarbons and / or polymers is discharged from the bottom of
Water filled with a solvent containing any foreign matter, polymer sludge or any other polar material is discharged from the bottom of the
The ED process shown in FIGS. 2-6 can be introduced for the regeneration of the lean solvent and the removal of the EDC raffinate solvent for various feedstock compositions. An exemplary combination of feedstock, solvent system and final product is shown in Table 2 below.
The principles, preferred embodiments and modes of operation of the present invention have been described above. However, the invention will not be construed as being limited to the specific embodiments discussed. Accordingly, the foregoing embodiments are to be considered illustrative rather than restrictive, and modifications may be made to these embodiments by those of ordinary skill in the art without departing from the scope of the invention as defined by the following claims. Should be recognized.
Claims (30)
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low polarity hydrocarbon stream containing water from the top of the EDC, and withdrawing a first solvent stream containing a polar hydrocarbon-selective water soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering a polar hydrocarbon-containing stream containing no polar hydrocarbon-selective water soluble solvent and a low polarity hydrocarbon from the top of the SRC, Removing a second solvent stream containing a lean solvent comprising a polar hydrocarbon-selective water-soluble solvent from the bottom of the first solvent stream;
(d) introducing a majority of the second solvent stream to the top of the EDC of step (a) as the polar hydrocarbon-selective aqueous solvent feed stream and introducing a small portion of the second solvent stream into the heavy hydrocarbon removal zone ;
(e) separating the first stream of water from the low-polarity hydrocarbon stream containing the water recovered from the top of the EDC in step (b) and separating the first stream from the polar hydrocarbon stream recovered from the top of the SRC in step (c) Separating the second water stream;
(f) introducing at least a portion of the first water stream and at least a portion of the second water stream into the heavy hydrocarbon removal zone, recovering the polar hydrocarbon-selective water soluble solvent phase, and removing the heavy hydrocarbon step;
(g) withdrawing the accumulated oil phase containing heavy hydrocarbons from the heavy hydrocarbon removal zone and recovering the aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the heavy hydrocarbon removal zone;
(h) separating water from the low-polarity hydrocarbon stream containing the water of step (b) to produce a low-polarity hydrocarbon stream introduced into the solvent-removal zone, and part of the first water stream of step (e) Introducing a portion of the second water stream or a portion of the first and second water streams into a solvent removal zone to extract the entrained polar hydrocarbon-selective water soluble solvent and remove the low polarity hydrocarbon;
(i) withdrawing the accumulated oil phase containing the low polarity hydrocarbon from the solvent removal zone and recovering an aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the solvent removal zone;
(j) removing the foreign material and polymer sludge from the aqueous phase from step (g) to obtain an aqueous phase free from solids; And
(k) introducing the aqueous phase from step (i) and the aqueous phase not comprising the solid material from step (j) into a vapor generator, and introducing stripping vapor introduced into the lower portion of the SRC in step (c) And evaporating water to form water.
Polar and low polarity hydrocarbons may be prepared by reacting a mixture of (a) aromatic and non-aromatic materials, (b) diolefins and olefins, (c) naphthenes and paraffins, or (d) styrene and C 8 aromatics Containing extractive distillation process.
The polar hydrocarbon-selective water-soluble solvent may be selected from the group consisting of sulfolane, polyalkylene glycol, N-substituted morpholine, furfural, acetonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, Nitrile, and mixtures thereof.
The polar hydrocarbon-selective water-soluble solvent is an extractive distillation process comprising water as a co-solvent.
The feedstock comprises aromatic and non-aromatic materials, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous sulfolane.
The feedstock comprises aromatic and non-aromatic materials, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous N-formylmorpholine.
The feedstock comprises butadiene and C 4 olefins, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous dimethylformamide.
Wherein the feedstock comprises styrene and a C 8 aromatics and the polar hydrocarbon-selective water soluble solvent comprises aqueous sulfolane.
Wherein the heavy hydrocarbon removal zone is an extractive distillation process comprising a thermal solvent regenerator.
Wherein each of the heavy hydrocarbon removal zone and the solvent removal zone comprises a continuous multi-stage countercurrent contacting device, a multi-stage mixed-precipitator or rotary contactor.
Wherein the heavy hydrocarbon removal zone comprises a water tank that functions as a decanter for separating heavy hydrocarbons and any sludge from a polar hydrocarbon-selective aqueous solvent and an aqueous phase containing water, the solvent removal zone comprising a trace amount of polar hydrocarbon- An extractive distillation process comprising a tank in which the low polarity hydrocarbons are separated from an aqueous phase containing water together with a selective aqueous solvent.
Extractive distillation process is operated under conditions to maximize benzene hoesueul in the first solvent stream by keeping an aromatic substance, and the EDC is, all the C 9 + hydrocarbons in the first solvent stream, wherein the raw material is an aromatic and non.
Wherein the feedstock comprises aromatic and non-aromatic materials and wherein the SRC operates under conditions that strip only C 8 and light hydrocarbons from the first solvent stream and retain all C 9 and heavy hydrocarbons in the second solvent stream Extraction distillation process.
Wherein the EDC is operated without liquid reflux at the top of the column.
In step (g), the thermal solvent regenerator is used as an auxiliary unit for the heavy hydrocarbon removal zone for sludge removal.
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low-polarity hydrocarbon stream containing water from the top of the EDC and discharging a first solvent stream comprising a polar hydrocarbon-selective water-soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering a polar hydrocarbon-selective water soluble solvent and a polar hydrocarbon stream free of low polarity hydrocarbons from the top of the SRC, Removing a second solvent stream containing a lean solvent comprising a polar hydrocarbon-selective aqueous solvent;
(d) introducing a majority of the second solvent stream to the top of the EDC of step (a) as the polar hydrocarbon-selective aqueous solvent feed stream and introducing a small portion of the second solvent stream into the heavy hydrocarbon removal zone ;
(e) separating the first stream of water from the water-containing low polarity hydrocarbon stream recovered from the top of the EDC in step (b) and separating the first stream from the polar hydrocarbon stream recovered from the top of the SRC in step (c) Separating the second water stream;
(f) introducing at least a portion of the first water stream and at least a portion of the second water stream into the heavy hydrocarbon removal zone, recovering the polar hydrocarbon-selective water soluble solvent phase, and removing the heavy hydrocarbon step;
(g) withdrawing the accumulated oil phase containing heavy hydrocarbons from the heavy hydrocarbon removal zone and recovering the aqueous phase containing the polar hydrocarbon-selective water-soluble solvent from the heavy hydrocarbon removal zone;
(h) recycling at least a portion of the low polarity hydrocarbon stream separated from the first water stream in step (e) to the top of the EDC to reduce the entrained polar hydrocarbon-selective water-soluble solvent in the upper vapor of the EDC To produce a low polarity hydrocarbon-containing stream without a polar hydrocarbon-selective aqueous solvent;
(j) removing the foreign material and polymer sludge from the aqueous phase from step (g) to obtain an aqueous phase free from solids; And
(k) introducing the solid phase-free aqueous phase from step (j) into the vapor generator, and evaporating water to form stripping vapor introduced into the lower portion of the SRC in step (c) Extraction distillation process.
(a) introducing a feedstock containing polar and low polarity hydrocarbons into the middle of an EDC (extractive distillation column) and introducing a polar hydrocarbon-selective aqueous solvent feed stream into the top of the EDC;
(b) recovering a low-polarity hydrocarbon stream containing water from the top of the EDC and discharging a first solvent stream comprising a polar hydrocarbon-selective water-soluble solvent and a polar hydrocarbon from the bottom of the EDC;
(c) introducing the first solvent stream into the middle of a solvent recovery column (SRC), recovering a polar hydrocarbon-selective water soluble solvent and a polar hydrocarbon stream free of low polarity hydrocarbons from the top of the SRC, Removing a second solvent stream containing a lean solvent comprising a polar hydrocarbon-selective aqueous solvent;
(d) introducing a large portion of the second solvent stream to the top of the EDC of step (a) as the polar hydrocarbon-selective aqueous solvent feed stream and introducing a small portion of the second solvent stream to the bottom of the flushing zone ;
(e) separating water from the low-polarity hydrocarbon stream containing water recovered from the top of the EDC in step (b) to produce a water stream from the lower water stream at a point below the entry point of the first and second solvent streams, Obtaining a low polarity hydrocarbon stream introduced into the zone;
(f) separating the second water stream from the polar hydrocarbon stream recovered from the top of the SRC in step (c);
(g) introducing at least a portion of the first water stream and the second water stream to the top of the flush zone, recovering the polar hydrocarbon-selective aqueous solvent which is an aqueous phase, and removing the low polarity hydrocarbon and heavy hydrocarbon step;
(h) discharging the accumulated low-polarity hydrocarbons and the accumulated oil phase containing the heavy hydrocarbons from the top of the flushing zone, and from the bottom of the flushing zone an aqueous phase containing a polar hydrocarbon-selective water-soluble solvent and optional sludge Discharging;
(i) removing foreign matter and polymer sludge from the aqueous phase of step (h) to obtain an aqueous phase free from solid matter; And
(j) introducing the solid phase-free aqueous phase from step (i) into the vapor generator, and evaporating water to form stripping vapor introduced into the lower portion of the SRC in step (c) Extraction distillation process.
The polar and low polarity hydrocarbon containing feedstock comprises a mixture of (a) aromatic and non-aromatic materials, (b) diolefins and olefins, (c) naphthenes and paraffins, and (d) styrene and C 8 aromatics Containing extractive distillation process.
The polar hydrocarbon-selective water-soluble solvent may be selected from the group consisting of sulfolane, polyalkylene glycol, N-substituted morpholine, furfural, acetonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, Nitrile, and mixtures thereof.
The polar hydrocarbon-selective water-soluble solvent is an extractive distillation process comprising water as a co-solvent.
The feedstock comprises aromatic and non-aromatic materials, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous sulfolane.
The feedstock comprises aromatic and non-aromatic materials, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous N-formylmorpholine.
The feedstock comprises butadiene and C 4 olefins, and the polar hydrocarbon-selective water-soluble solvent comprises aqueous dimethylformamide.
Wherein the feedstock comprises styrene and a C 8 aromatics and the polar hydrocarbon-selective water soluble solvent comprises aqueous sulfolane.
The flush area may include a continuous multi-stage countercurrent contact device, an extractive distillation process comprising a multi-stage mixed-precipitator or rotary contactor.
Wherein the flush zone comprises a water tank that functions as a decanter for separating the polar hydrocarbon, heavy hydrocarbons, and any sludge from the polar hydrocarbon-selective water soluble solvent and the aqueous phase containing water.
Extractive distillation process is operated under conditions to maximize benzene hoesueul in the first solvent stream by keeping an aromatic substance, and the EDC is, all the C 9 and heavier hydrocarbons in the first solvent stream, wherein the raw material is an aromatic and non.
Wherein the feedstock comprises aromatic and non-aromatic materials and wherein the SRC operates under conditions that strip only C 8 and light hydrocarbons from the first solvent stream and retain all C 9 and heavy hydrocarbons in the second solvent stream Extraction distillation process.
Wherein the EDC is operated without liquid reflux at the top of the column.
In step (g), the thermal solvent regenerator is an extractive distillation process used as an auxiliary unit for a flush zone for sludge removal.
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| CN102719270A (en) * | 2012-06-07 | 2012-10-10 | 天津大学 | Method and system for separating saturated alkane in liquid hydrocarbon material flow from mixed primary alcohol |
| CN103657121B (en) * | 2012-09-17 | 2015-11-25 | 中国石油化工股份有限公司 | A kind of renovation process of extracting, rectifying and separating phenylethylene solvent for use |
| CN103897720B (en) * | 2012-12-27 | 2016-02-10 | 中国石油天然气股份有限公司 | Method for extracting, rectifying, separating and reforming raffinate oil by composite solvent |
| CN103193577B (en) * | 2013-03-25 | 2014-12-10 | 烟台大学 | Method for extracting, rectifying and separating butane from butylene by ternary mixed solvent |
| US9221729B1 (en) * | 2015-02-23 | 2015-12-29 | Allnew Chemical Technology Company | Extractive distillation for aromatics recovery |
| EP3390330B1 (en) | 2015-12-18 | 2023-07-19 | SABIC Global Technologies B.V. | Methods for producing 1,3-butadiene |
| KR102078454B1 (en) | 2018-05-02 | 2020-02-17 | 주식회사 알로이스 | Method for preventing copying of a multimedia device through an authentication server |
| CN109019740B (en) * | 2018-07-31 | 2021-05-11 | 大连理工大学 | Sulfolane wastewater treatment method |
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2008
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- 2008-12-12 EP EP08873651A patent/EP2257353B1/en active Active
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Also Published As
| Publication number | Publication date |
|---|---|
| EP2559466A1 (en) | 2013-02-20 |
| EP2257353A4 (en) | 2011-03-16 |
| WO2009120181A1 (en) | 2009-10-01 |
| CN102036726B (en) | 2013-07-03 |
| EP2257353B1 (en) | 2012-09-05 |
| CN102036726A (en) | 2011-04-27 |
| EP2559466B1 (en) | 2013-12-04 |
| EP2257353A1 (en) | 2010-12-08 |
| KR20110010701A (en) | 2011-02-07 |
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